In recent years, cases are increasing in which on-board devices, such as a drive recorder, a digital tachometer, etc., that measure data related to travel of vehicles are mounted on the vehicles. Also, there are cases for example where an incident in which the brake is suddenly stepped on in a vehicle (which may also be referred to as a sudden braking incident hereinafter in some cases) is detected from the acceleration of the vehicle measured by the on-board device and information of the occurrence of the sudden braking incident is used to alarm the driver, to detect the occurrence of an accident or for other purposes.
In relation to this, a technique is known in which an acceleration sensor that detects the acceleration in the traveling direction is installed in a vehicle, whether appropriate driving is being performed is diagnosed upon starting and stopping and correction of inappropriate driving that depends on tendencies of the driver such as sudden starting, sudden stopping, etc. is conducted (see Document 1 for example). Also, a technique for providing a vehicle state determination device that can preferably determine the state of a vehicle even from limited information such as the acceleration etc. obtained from the sensor is known (see Document 2 for example). A method for classifying pieces of accident/near miss data and other pieces of data precisely and automatically is also known (see Document 3 for example).
Document 1: Japanese Laid-open Patent Publication No. 2006-341806
Document 2: International Publication Pamphlet No. WO2014/080507
Document 3: Mori, Midori, et al, “An Effective Automatic Classification Method of Drive Recorder Data without a Threshold”, The Japanese Journal of Ergonomics, Vol. 49, No. Supplement pp. S248-S249, 2013